Wrist-pin-locking device



Sept. 22, 1925.

J. H. WENDELL ET AL WRIST PIN LOCKING DEVICE Filed July 26, 1924 w/ IX Win E 655 541F795. 7WOMP50/V dthvu Patented Sept. 22, 1925.

UNITED STATES PATENT OFFICE.

JUSTIN H. WENDELL AND RALPH E. THOMPSON, OF PORTSMOUTH, NEW HAMPSHIRE.

WRIST-PIN-LOCKING Application filed July 26, 1924. Serial No. 728,495.

To all whom it may concern:

Be it known that we, JUsTIN H. VVENDELL and RALPH E. THOMPSON, citizens of the United States, residing at Portsmouth, in the county of Rockingham and State of NewHampshire, have invented certain new and useful Improvements in VVrist-Pin- Locking Devices, of which the following is a specification.

This invention appertains to internal combustion engines and more particularly to means for retaining the wrist pin in place in the piston and against accidental sliding movement therein.

The primary object of the present invention is the provision of novel means of fastening a wrist pin in a piston, the means being so constructed as to eliminate the use of set screws, cotter pins, or the like, and to absolutely preclude sliding movement of the wrist pin in the piston, thereby eliminating the possibility of the wrist pin working loose and scoring the walls of the cylinder.

A further object of the invention is the provision of a wrist pin having a seat formed on one or both ends thereof against which is adapted to fit a resilient split ring or washer, the ring or washer being seated in a suitable groove in the piston.

A still further object of the invention is to provide an improved pin locking means of the above character, which will be durable and efficient in use, one that will be simple and easy to manufacture, and one which can be placed upon the market and incorporated with a piston at a small cost. W

With these and other objects in view, the invention consists in the novel construction, arrangement and formation of parts, as will be hereinafter morev specifically described,

claimed, and illustrated in the accompany-- ing drawings,'in which drawings:

igure 1 is a fragmentary longitudinal central section through a piston of the ty e embodying a rotary wrist pin showing t e invention applied thereto,

Figure 2 is a longitudinal section through the wrist pin bushing showing the annular groove or seat therein for receiving the looking ring,

Figure 3 is a detailed elevation of the resilient split locking ring or washer,

Figure 4 is a fragmentary longitudinal section through a piston of the type embodying a stationary Wrist pin showlng the 1nvention incorporated therewith, and

Figure -5 is a side elevation of a piston of the type embodying a stationary wrist pin showing the novel locking means incorporated therewith.

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views, the letter A generally indicatesa piston of the type embodying a rotary wrist pin B. As shown the piston A includes the usual skirt provided with inwardly directed bearing sleeves 11 which in turn support the Wrist pin bushings 12.

In accordance with this invention the wrist pin B is formed relatively shorter than the diameter of the skirt 10 of the piston A, so that the terminals thereof end inwardly of the outer face of the piston and the terminals of the wrist pin are slightly beveled at their edge to lie in an inclined seat 13 for a purpose, which will be hereinafter more fully described. It is to be noted that the wrist pin B is rotatably mountedwithin the wrist pin bushings 12 in the usual mam.

ner. Each of the wrist pin bushings 12 adjacent to the outer terminals thereofis provided with an annular groove or seat 14: and this groove or seat 14 is adapted to removabl receive the locking ring or washer 15. This locking ring or washer 15 is of a resilient nature and is split to permit the expansion and contraction thereof in orderto facilitate the placing of the ring in the said groove 14.

When it is desired to place the wrist p'in B in position, it is merely necessary to slide the same in the bushings 12 in the usual manner and then force the split resilient ring 15 in place in the groove 14: by the use of any desired tool and these rings will fit against the seat 13 formed on the terminals of the wrist pin and it is obvious that sliding movement of the wrist pin B in the iston A is entirely eliminated and thus all likelihood of the scoring of the inside of the cylinder by a loose wrist pin is prevented. I

When it isdesired to remove the wrist pin the locking rings 15 are removed by prying them from. their seat 14 by the use of a suitable tool such as a screwdriver or the vlike.

In Figures 4 and 5 I have shown the in-' vention adapted to a piston C of the type which supports a non-rotatable wrist-pin D. The piston C in this form consists of'the usual skirt 20 provided at the desired diametrically disposed points, with the bearing sleeves 21 and 22. As clearly shown in Figure 4 of the drawings the sleeve 21 is provided with an inwardly extending longitudinslly disposed groove 23 which terminates short ofthe inner end thereof.

The wrist pin D in this form is also formed of at less length than the diameter of the piston and has its terminals provided with beveled seats 24:. Une end of the wrist pin D is adapted to receive a rearwardly extending key 25 which is adapted to fit within the way 23. It can be seen that the key 25 and'keyway 23 prevent rotation of the pin and: also sliding movement thereof in one direction.

In order. to prevent sliding movement of the pin D in theopposite direction, the interior of the sleeve 21 is provided adjacentto the outer face of the said pin D with an annular seat or groove 26 in which is adapted to fit e resilient split locking ring 2'2' of the same type as the ring-15 described in the form of the invention in Figures 1 to 3 inclusive. As shown this ring 2'? also fits on the seat 24 of the wrist pin D and it is obvious that sliding movement of the wrist pin is prevented by the locking key 25 and locking ring 27.

Changes in details may he made without departing from the spirit or the scope of this invention, but:

What we clenn as new is:

menses 1. The combination with a piston having it seat formed therein and a wrist pin provided with a beveled sent at its terminals of a locking device for the wrist pin comprising a removable locking ring fitted in the seat of the piston and against the seat of the wrist pin.

2 The combination with e piston including inwardly directed bearing sleeves, bearing bushings fitted in the sleeve having annular grooves formed therein adjacent to the outer ends thereof and a wrist pin ro- 1 tatably fitted in the bushings designed with beveled seats at the terminals, of means for preventing sliding movement of the wrist pin, in the bushings including resilient split rings fitted in the grooves in the bushings in engegement with the beveled seats of the wrist pin: I

3. The combination with e piston provided with wrist pin bearings formed with circumferential grooves adjacent their outer ends, of a wrist pin received in the bearings and having its ends tapered, and a split resilient ring received in each of the bearings and engaged in the grooves and contecting" with the tapered ends of the wrist pini In testimony whereof we 'afix our signe turesn JUSTIN H. WEN DELL. RALPH E. THUMPSONQ 

